scholarly journals Sirtuin 5 is Regulated by the SCF-Cyclin F Ubiquitin Ligase and is Involved in Cell Cycle Control

2020 ◽  
Author(s):  
Christine A. Mills ◽  
Xianxi Wang ◽  
Dhaval P. Bhatt ◽  
Paul A. Grimsrud ◽  
Jacob Peter Matson ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Cell Cycle Control ◽  
Genetically Modify ◽  
Ubiquitin Proteasome System ◽  
Subsequent Increase ◽  
Cycle Progression ◽  
A Cell ◽  
F Box Protein ◽  
Cyclin F

The ubiquitin-proteasome system is essential for cell cycle progression. Cyclin F is a cell cycle regulated substrate adapter F-box protein for the SKP1/CUL1/F-box (SCF) family of E3 ubiquitin ligases. Despite its importance in cell cycle progression, identifying SCFCyclin F substrates has remained challenging. Since Cyclin F overexpression rescues a yeast mutant in the cdc4 gene, we considered the possibility that other genes that genetically modify cdc4 mutant lethality could also encode Cyclin F substrates. We identified the mitochondrial and cytosolic deacylating enzyme Sirtuin 5 (SIRT5) as a novel Cyclin F substrate. SIRT5 has been implicated in metabolic processes, but its connection to the cell cycle is not known. We show that Cyclin F interacts with, and controls the ubiquitination, abundance, and stability of SIRT5. We show SIRT5 knockout results in a diminished G1 population, and subsequent increase in both S and G2/M. Global proteomic analyses reveal CDK signaling changes congruent with the cell cycle changes in SIRT5 knockout cells. Together these data demonstrate that SIRT5 is regulated by Cyclin F and suggest a connection between SIRT5, cell cycle regulation, and metabolism.

scholarly journals Regulation of cell cycle drivers by Cullin-RING ubiquitin ligases

2020 ◽  
Vol 52 (10) ◽  
pp. 1637-1651 ◽  
Author(s):  
Sang-Min Jang ◽  
Christophe E. Redon ◽  
Bhushan L. Thakur ◽  
Meriam K. Bahta ◽  
Mirit I. Aladjem
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Cell Cycle Progression ◽  
Ubiquitin Ligases ◽  
Anaphase Promoting Complex ◽  
Cycle Progression ◽  
Cellular Processes ◽  
Cellular Pathways ◽  
Regulation Of Cell Cycle ◽  
F Box Protein

Abstract The last decade has revealed new roles for Cullin-RING ubiquitin ligases (CRLs) in a myriad of cellular processes, including cell cycle progression. In addition to CRL1, also named SCF (SKP1-Cullin 1-F box protein), which has been known for decades as an important factor in the regulation of the cell cycle, it is now evident that all eight CRL family members are involved in the intricate cellular pathways driving cell cycle progression. In this review, we summarize the structure of CRLs and their functions in driving the cell cycle. We focus on how CRLs target key proteins for degradation or otherwise alter their functions to control the progression over the various cell cycle phases leading to cell division. We also summarize how CRLs and the anaphase-promoting complex/cyclosome (APC/C) ligase complex closely cooperate to govern efficient cell cycle progression.

scholarly journals Evidence for a dual role for TC4 protein in regulating nuclear structure and cell cycle progression.

1994 ◽  
Vol 125 (4) ◽  
pp. 705-719 ◽  
Author(s):  
S Kornbluth ◽  
M Dasso ◽  
J Newport
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Nuclear Structure ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Nuclear Assembly ◽  
Egg Extracts ◽  
A Cell ◽  
Xenopus Egg Extracts

TC4, a ras-like G protein, has been implicated in the feedback pathway linking the onset of mitosis to the completion of DNA replication. In this report we find distinct roles for TC4 in both nuclear assembly and cell cycle progression. Mutant and wild-type forms of TC4 were added to Xenopus egg extracts capable of assembling nuclei around chromatin templates in vitro. We found that a mutant TC4 protein defective in GTP binding (GDP-bound form) suppressed nuclear growth and prevented DNA replication. Nuclear transport under these conditions approximated normal levels. In a separate set of experiments using a cell-free extract of Xenopus eggs that cycles between S and M phases, the GDP-bound form of TC4 had dramatic effects, blocking entry into mitosis even in the complete absence of nuclei. The effect of this mutant TC4 protein on cell cycle progression is mediated by phosphorylation of p34cdc2 on tyrosine and threonine residues, negatively regulating cdc2 kinase activity. Therefore, we provide direct biochemical evidence for a role of TC4 in both maintaining nuclear structure and in the signaling pathways that regulate entry into mitosis.

Cdk1-Dependent Phosphorylation ofNPM Overrides G2/M Checkpoint and Increases Leukemic Blasts in Mice

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1322-1322
Author(s):  
Wei Du ◽  
Yun Zhou ◽  
Suzette Pike ◽  
Qishen Pang
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Cell Cycle Control ◽  
Xenograft Model ◽  
Phosphorylation Sites ◽  
M Cell ◽  
Cycle Progression ◽  
Hematopoietic Stem ◽  
Cycle Arrest ◽  
Regulation Of Cell Cycle

Abstract An elevated level of nucleophosmin (NPM) is often found in actively proliferative cells including human tumors. To identify the regulatory role for NPM phosphorylation in proliferation and cell cycle control, a series of mutants targeting the consensus cyclin-dependent kinase (CKD) phosphorylation sites was created to mimic or abrogate either single-site or multi-site phosphorylation. Cells expressing the phosphomimetic NPM mutants showed enhanced proliferation and G2/M cell-cycle transition; whereas nonphosphorylatable mutants induced G2/M cell-cycle arrest. Simultaneous inactivation of two CKD phosphorylation sites at Ser10 and Ser70 (S10A/S70A, NPM-AA) induced phosphorylation of Cdk1 at Tyr15 (Cdc2Tyr15) and increased cytoplasmic accumulation of Cdc25C. Strikingly, stress-induced Cdk1Tyr15 and Cdc25C sequestration were completely suppressed by expression of a double phosphomimetic NPM mutant (S10E/S70E, NPM-EE). Further analysis revealed that phosphorylation of NPM at both Ser10 and Ser70 sites were required for proper interaction between Cdk1 and Cdc25C in mitotic cells. Moreover, the NPM-EE mutant directly bound to Cdc25C and prevented phosphorylation of Cdc25C at Ser216 during mitosis. Finally, NPM-EE overrided stress-induced G2/M arrest, increased peripheral-blood blasts and splenomegaly in a NOD/SCID xenograft model, and promoted leukemia development in Fanconi mouse hematopoietic stem/progenitor cells. Thus, these findings reveal a novel function of NPM on regulation of cell-cycle progression, in which Cdk1-dependent phosphorylation of NPM controls cell-cycle progression at G2/M transition through modulation of Cdc25C activity.

Validation of a cell cycle progression score for 5-year mortality risk in patients with stage I non-small cell lung cancer.

2015 ◽  
Vol 33 (15_suppl) ◽  
pp. 7522-7522
Author(s):  
Takashi Eguchi ◽  
Kadota Kyuichi ◽  
Brent Evans ◽  
Camelia S. Sima ◽  
Thaylon Davis ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Cell Cycle ◽  
Small Cell Lung Cancer ◽  
Cell Lung Cancer ◽  
Mortality Risk ◽  
Cell Cycle Progression ◽  
Small Cell ◽  
Small Cell Lung ◽  
Cycle Progression ◽  
A Cell

scholarly journals Regulation of Skp2 Expression and Activity and Its Role in Cancer Progression

2010 ◽  
Vol 10 ◽  
pp. 1001-1015 ◽  
Author(s):  
Chia-Hsin Chan ◽  
Szu-Wei Lee ◽  
Jing Wang ◽  
Hui-Kuan Lin
Keyword(s):  
Cell Cycle ◽  
Cancer Progression ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Protein Levels ◽  
Human Cancers ◽  
Attractive Therapeutic Target ◽  
Skp2 Protein ◽  
Regulation Of Cell Cycle ◽  
F Box Protein

The regulation of cell cycle entry is critical for cell proliferation and tumorigenesis. One of the key players regulating cell cycle progression is the F-box protein Skp2. Skp2 forms a SCF complex with Skp1, Cul-1, and Rbx1 to constitute E3 ligase through its F-box domain. Skp2 protein levels are regulated during the cell cycle, and recent studies reveal that Skp2 stability, subcellular localization, and activity are regulated by its phosphorylation. Overexpression of Skp2 is associated with a variety of human cancers, indicating that Skp2 may contribute to the development of human cancers. The notion is supported by various genetic mouse models that demonstrate an oncogenic activity of Skp2 and its requirement in cancer progression, suggesting that Skp2 may be a novel and attractive therapeutic target for cancers.

scholarly journals Kinetochore chemistry is sensitive to tension and may link mitotic forces to a cell cycle checkpoint.

1995 ◽  
Vol 130 (4) ◽  
pp. 929-939 ◽  
Author(s):  
R B Nicklas ◽  
S C Ward ◽  
G J Gorbsky
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Cell Cycle Checkpoint ◽  
Cycle Progression ◽  
Anaphase Onset ◽  
Cycle Checkpoint ◽  
A Cell ◽  
Protein Dephosphorylation ◽  
Regulation Of Cell Cycle ◽  
Checkpoint Signal

Some cells have a quality control checkpoint that can detect a single misattached chromosome and delay the onset of anaphase, thus allowing time for error correction. The mechanical error in attachment must somehow be linked to the chemical regulation of cell cycle progression. The 3F3 antibody detects phosphorylated kinetochore proteins that might serve as the required link (Gorbsky, G. J., and W. A. Ricketts. 1993. J. Cell Biol. 122:1311-1321). We show by direct micromanipulation experiments that tension alters the phosphorylation of kinetochore proteins. Tension, whether from a micromanipulation needle or from normal mitotic forces, causes dephosphorylation of the kinetochore proteins recognized by 3F3. If tension is absent, either naturally or as a result of chromosome detachment by micromanipulation, the proteins are phosphorylated. Equally direct experiments identify tension as the checkpoint signal: tension from a microneedle on a misattached chromosome leads to anaphase (Li, X., and R. B. Nicklas. 1995. Nature (Lond.). 373:630-632), and we show here that the absence of tension caused by detaching chromosomes from the spindle delays anaphase indefinitely. Thus, the absence of tension is linked to both kinetochore phosphorylation and delayed anaphase onset. We propose that the kinetochore protein dephosphorylation caused by tension is the all clear signal to the checkpoint. The evidence is circumstantial but rich. In any event, tension alters kinetochore chemistry. Very likely, tension affects chemistry directly, by altering the conformation of a tension-sensitive protein, which leads directly to dephosphorylation.

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